General electronic devices have external appearances that may be affected by the materials or the arrangement of components therein. A plurality of members relating to the external appearances may be included as parts of the external appearances of the electronic devices. For example, a display, a receiver, a front camera, and the like may be arranged on the front exterior of an electronic device, and a rear camera, a flash, a speaker hole, and the like may be arranged on the rear exterior of the electronic device. Furthermore, a side key, a USB connector, an earphone jack connector, a microphone hole, and the like may be arranged on side surfaces of the electronic device. The arrangement of the components may vary according to the exterior designs of electronic products.
Components relating to the external appearance of an electronic device, which are disposed in the electronic device, may include exterior members. In particular, among the exterior members, a movable exterior member that undergoes a physical press or an exterior member with an insertion hole may have low waterproofing performance. For example, a volume control key or a power key, which is disposed on a side surface of the electronic device, may move while the top of the key is exposed to the outside. Foreign substances (such as moisture) may infiltrate into the electronic device through a gap between a moving member and a case frame to damage a printed circuit board, etc.